At Oracle OpenWorld 2007, Oracle announced new virtualization software, causing a firestorm of interest and a decline in competitor vmware's stock. Oracle VM, which can be downloaded free, is based on the Xen open-source hypervisor product. With all of the hype, Oracle managers are now struggling to understand how Oracle VM can fit into their enterprise. Let's explore how virtualization is becoming part of the 21st century database toolbox.
It's back to the future for the Oracle database world. The inefficient one server/one database approach of 1990s client-server technology is long gone and Oracle shops are now re-consolidating their data resources, moving back to the mainframe-like centralization of the 1980s. While Oracle touts VM as a latest-and-greatest solution, we need to remember that server virtualization has been around for decades.
Virtualization is simply the partitioning of a server in order to host multiple OS environments. Whether it's running virtual Windows on your Macintosh laptop or partitioning a 128 CPU mainframe, IT managers are leveraging virtualization solutions to consolidate multiple OS environments. At a high level, virtualization is the process of segregating server resources in a homogeneous environment, but it's most commonly used to host different operating systems within a single monolithic server -- and this is a step toward OS independence.
A brief history of Oracle virtualization
Oracle rose to dominate the database market primarily because of its ability to run on more than 60 platforms, everything from a mainframe to a Macintosh. However, Oracle soon faced the challenge of running multiple OS environments within the same server. In early 2005, Oracle announced that their version of VMWare would come pre-loaded with both Linux and Oracle, making it easier than ever to run Linux on a MS Windows server. Oracle then embraced the idea of server consolidation via the 11g Grid Initiative. At Openworld 2007, Oracle claimed that 99% of their customers run multiple instances within a single host machine and so began pushing the new VM product.
Although VM is free for download, support will cost $499/year for 1 or 2 CPU systems and $999/year for others. Thus far, VM is limited to Intel platforms, and will support only Linux and Windows servers. Oracle VM also offers a GUI management console (HTML-based) to allow easy management of both the overall OS and the virtual machines running under the master OS. Oracle is incorporating virtualization along several areas:
- SOA - Oracle plans to incorporate Oracle VM into their Fusion stack, allowing a method for unifying diverse applications onto a single server using SOAP. Oracle President Charles Phillips notes that Oracle VM will help SAP shops migrate from their foreign ERP's to Oracle Applications. "We want to help customers integrate their software with third-party applications made in Germany," he said at OpenWorld.
- Consolidating heterogeneous environments - Oracle VM is useful for shops that wish to consolidate different applications onto a single hardware platform. A common example is running Windows side-by-side with UNIX (HP/UX, Solaris, AIX, Linux) on a large monolithic server. For example, instead of buying six 2 CPU servers, you can buy one 4 CPU 64-bit server with 16 GB RAM, and save a bundle of cash. For details, see my notes on the trend towards Oracle server consolidation.
- Oracle OLAP consolidation - Mark Rittman notes the benefits of running Oracle 10g R2 with virtualization with the Oracle Business Intelligence Suite (OLAP).
- Oracle application server - Oracle Application Server can be run with Oracle on a single server using VM. John Garmany has some good notes on Oracle App Server and virtualization.
- Students - Using virtualization is popular among people who want to learn RAC on a personal computer, whereby VM can allow a single server to mimic several RAC nodes.
The second age of mainframe computing
The early 21st century is seeing the second age of mainframe computing, a change away from the minicomputer hardware architectures of past decades. Instead of small, independent servers, the major hardware vendors are pushing large servers with transparent sharing of hardware resources, coining the term "partitionable servers."
But how does Oracle VM fit into these existing virtualization techniques? There are some shortcomings of Oracle VM:
- Unshared resources - Server resources cannot be easily shared, and it counteracts the goal of server consolidation to leverage on a massive shared computing resource.
- Measurable overhead - We must remember that Oracle VM imposes some overhead, and a savvy DBA will always perform a workload benchmark using other alternatives (containers, para-virtualization) before choosing virtualization.
- Bad for the DBA job market - Server consolidation is bad for the DBA job market because one of the main reasons for consolidating hardware resources is the savings from reducing DBA staff. A typical shop can save a million dollars a year by removing a dozen DBAs. The one-server/one-application paradigm has proven too expensive, so many enterprises are now moving back to the centralized architectures of old.
In sum, Oracle VM fits nicely into the strategic plans for server consolidation but the savvy Oracle professional must recognize that virtualization has both benefits and limitations. It remains to be seen whether VM will become a permanent part of the data center, of if it will be only used as a stopgap tool for shops that want to run Windows in a Linux environment.
About the author
Donald K. Burleson has been a database administrator since the 1980s and manages the USA's largest remote DBA support service. He is also a popular author and serves as series editor for Rampant TechPress, a leading provider of Oracle technical books.